Minimization of the Number of Cooling Holes in Internally Cooled Turbine Blades

This work represents an extension of the earlier research on inverse determination of proper locations and sizes of a given number of coolant flow passages (holes) subject to specified surface temperatures and heat fluxes. The methodology is extended to allow designer to guess the required number of holes and the minimal allowable diameter of a hole. A constrained optimization algorithm is then used to minimize the total number of cooling holes, while satisfying user-specified hot surface temperatures and heat fluxes. Premature termination of the optimization process due to the existence of local minimas has been satisfactorily resolved by automatic switching of the objective function formulation whenever the local minima is detected. The convergence criteria of the iterative process, which can be specified by the user, was found to have a strong influence on the accuracy of the entire inverse design optimization algorithm.Copyright © 1991 by ASME